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Suppression of Fusarium oxysporum and induced resistance of plants involved in the biocontrol of Cucumber Fusarium Wilt by Streptomyces bikiniensis HD-087

Zhao, Shuai, Du, Chun-Mei, Tian, Chang-Yan
World journal of microbiology & biotechnology 2012 v.28 no.9 pp. 2919-2927
Fusarium oxysporum, Fusarium wilt, Streptomyces bikiniensis, biological control, cell membranes, chlorophyll, conidia, cucumbers, cytoplasm, economics, fermentation, fungi, germination, hyphae, induced resistance, leaves, lipids, metabolites, nucleotide sequences, pathogens, peroxidase, phenylalanine ammonia-lyase, ribosomal RNA, sequence analysis, sugars
Cucumber Fusarium Wilt, caused by Fusarium oxysporum f. sp. cucumerinum, which usually leads to severe economic damage, is a common destructive disease worldwide. To date, no effective method has yet been found to counteract this disease. A fungal isolate, designated HD-087, which was identified as Streptomyces bikiniensis using physiological-biochemical identification and 16S rRNA sequence analysis, is shown to possess distinctive inhibitory activity against F. oxysporum. The fermentation broth of HD-087 leads to certain abnormalities in pathogen hyphae. It peroxidizes cell membrane lipids, which leads to membrane destruction along with cytoplasm leakage. This broth also restrains germination of the conidia. The activities of the enzymes peroxidase, phenylalanine ammonia-lyase, and β-1,3-glucanase in cucumber leaves were dramatically increased after treated with fermentation broth of HD-087. The levels of chlorophyll and soluble sugars were also found to be increased, with the relative conductivity of leaves being reduced. In short, the metabolites of strain HD-087 can effectively suppress F. oxysporum and trigger induced resistance in cucumber.